diff --git a/extensions/voice-call/src/providers/twilio/api.test.ts b/extensions/voice-call/src/providers/twilio/api.test.ts
new file mode 100644
index 00000000000..5fb761a3257
--- /dev/null
+++ b/extensions/voice-call/src/providers/twilio/api.test.ts
@@ -0,0 +1,85 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { twilioApiRequest } from "./api.js";
+
+const originalFetch = globalThis.fetch;
+
+describe("twilioApiRequest", () => {
+  afterEach(() => {
+    globalThis.fetch = originalFetch;
+  });
+
+  it("posts form bodies with basic auth and parses json", async () => {
+    globalThis.fetch = vi.fn(async () => {
+      return new Response(JSON.stringify({ sid: "CA123" }), { status: 200 });
+    }) as typeof fetch;
+
+    await expect(
+      twilioApiRequest({
+        baseUrl: "https://api.twilio.com",
+        accountSid: "AC123",
+        authToken: "secret",
+        endpoint: "/Calls.json",
+        body: {
+          To: "+14155550123",
+          StatusCallbackEvent: ["initiated", "completed"],
+        },
+      }),
+    ).resolves.toEqual({ sid: "CA123" });
+
+    const [url, init] = vi.mocked(globalThis.fetch).mock.calls[0] ?? [];
+    expect(url).toBe("https://api.twilio.com/Calls.json");
+    expect(init).toEqual(
+      expect.objectContaining({
+        method: "POST",
+        headers: {
+          Authorization: `Basic ${Buffer.from("AC123:secret").toString("base64")}`,
+          "Content-Type": "application/x-www-form-urlencoded",
+        },
+      }),
+    );
+    expect(String(init?.body)).toBe("To=%2B14155550123&StatusCallbackEvent=initiated&StatusCallbackEvent=completed");
+  });
+
+  it("passes through URLSearchParams, allows 404s, and returns undefined for empty bodies", async () => {
+    const responses = [
+      new Response(null, { status: 204 }),
+      new Response("missing", { status: 404 }),
+    ];
+    globalThis.fetch = vi.fn(async () => responses.shift()!) as typeof fetch;
+
+    await expect(
+      twilioApiRequest({
+        baseUrl: "https://api.twilio.com",
+        accountSid: "AC123",
+        authToken: "secret",
+        endpoint: "/Calls.json",
+        body: new URLSearchParams({ To: "+14155550123" }),
+      }),
+    ).resolves.toBeUndefined();
+
+    await expect(
+      twilioApiRequest({
+        baseUrl: "https://api.twilio.com",
+        accountSid: "AC123",
+        authToken: "secret",
+        endpoint: "/Calls/missing.json",
+        body: {},
+        allowNotFound: true,
+      }),
+    ).resolves.toBeUndefined();
+  });
+
+  it("throws twilio api errors for non-ok responses", async () => {
+    globalThis.fetch = vi.fn(async () => new Response("bad request", { status: 400 })) as typeof fetch;
+
+    await expect(
+      twilioApiRequest({
+        baseUrl: "https://api.twilio.com",
+        accountSid: "AC123",
+        authToken: "secret",
+        endpoint: "/Calls.json",
+        body: {},
+      }),
+    ).rejects.toThrow("Twilio API error: 400 bad request");
+  });
+});
diff --git a/extensions/voice-call/src/webhook/stale-call-reaper.test.ts b/extensions/voice-call/src/webhook/stale-call-reaper.test.ts
new file mode 100644
index 00000000000..a7f2528513b
--- /dev/null
+++ b/extensions/voice-call/src/webhook/stale-call-reaper.test.ts
@@ -0,0 +1,83 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { startStaleCallReaper } from "./stale-call-reaper.js";
+
+describe("startStaleCallReaper", () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date("2026-03-22T12:00:00.000Z"));
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+    vi.restoreAllMocks();
+  });
+
+  it("returns null when disabled or non-positive", () => {
+    const manager = {
+      getActiveCalls: vi.fn(() => []),
+      endCall: vi.fn(),
+    };
+
+    expect(startStaleCallReaper({ manager: manager as never })).toBeNull();
+    expect(startStaleCallReaper({ manager: manager as never, staleCallReaperSeconds: 0 })).toBeNull();
+  });
+
+  it("reaps stale calls and ignores fresh ones", async () => {
+    const endCall = vi.fn(async () => {});
+    const manager = {
+      getActiveCalls: vi.fn(() => [
+        {
+          callId: "call-stale",
+          startedAt: Date.now() - 61_000,
+          state: "active",
+        },
+        {
+          callId: "call-fresh",
+          startedAt: Date.now() - 10_000,
+          state: "active",
+        },
+      ]),
+      endCall,
+    };
+
+    const stop = startStaleCallReaper({
+      manager: manager as never,
+      staleCallReaperSeconds: 60,
+    });
+
+    await vi.advanceTimersByTimeAsync(30_000);
+
+    expect(endCall).toHaveBeenCalledTimes(1);
+    expect(endCall).toHaveBeenCalledWith("call-stale");
+
+    stop?.();
+  });
+
+  it("logs and swallows endCall failures", async () => {
+    const warn = vi.spyOn(console, "warn").mockImplementation(() => {});
+    const manager = {
+      getActiveCalls: vi.fn(() => [
+        {
+          callId: "call-stale",
+          startedAt: Date.now() - 61_000,
+          state: "active",
+        },
+      ]),
+      endCall: vi.fn(async () => {
+        throw new Error("network");
+      }),
+    };
+
+    const stop = startStaleCallReaper({
+      manager: manager as never,
+      staleCallReaperSeconds: 60,
+    });
+
+    await vi.advanceTimersByTimeAsync(30_000);
+    await Promise.resolve();
+
+    expect(warn).toHaveBeenCalledWith("[voice-call] Reaper failed to end call call-stale:", expect.any(Error));
+
+    stop?.();
+  });
+});